The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Engine control includes control of parameters in the operation of an engine based upon a desired engine output, including an engine speed and an engine load, and resulting operation, for example, including engine emissions. Parameters controlled by engine control methods include air flow, fuel flow, and intake and exhaust valve settings.
Boost air can be provided to an engine to provide an increased flow of air to the engine relative to a naturally aspirated intake system to increase the output of the engine. A turbocharger utilizes pressure in an exhaust system of the engine to drive a compressor providing boost air to the engine. Exemplary turbochargers can include variable geometry turbochargers (VGT), enabling modulation of boost air provided for given conditions in the exhaust system. A supercharger utilizes mechanical power from the engine, for example as provided by an accessory belt, to drive a compressor providing boost air to the engine. Engine control methods control boost air in order to control the resulting combustion within the engine and the resulting output of the engine.
Exemplary engines may utilize two-stage boosting wherein a secondary turbocharger is utilized to increase air flow to the engine. The secondary turbocharger may be an electrical turbocharger. Methods of controlling an engine having two-stage boosting varies from the control methods of a single-stage boosted engine. The control may be achieved using unique model based control of the electrical boosting system using at least one of power split control models and power balance control models.